/*	bind.c
 *
 *	This file is for functions having to do with key bindings,
 *	descriptions, help commands and startup file.
 *
 *	Written 11-feb-86 by Daniel Lawrence
 *	Modified by Petri Kutvonen
 */

#include <stdio.h>

#include "estruct.h"
#include "edef.h"
#include "efunc.h"
#include "fileio.h"
#include "line.h"


/*	possible names and paths of help files under different OSs	*/
static const char *pathname[] = {
#if	MSDOS
	"emacs.rc",
	"emacs.hlp",
	"\\sys\\public\\",
	"\\usr\\bin\\",
	"\\bin\\",
	"\\",
	""
#endif

#if	V7 | BSD | USG
	".emacsrc",
	"emacs.hlp",
#if	PKCODE
	"/usr/global/lib/", "/usr/local/bin/", "/usr/local/lib/",
#endif
	"/usr/local/", "/usr/lib/", ""
#endif

#if	VMS
{
	"emacs.rc", "emacs.hlp", "",
#if	PKCODE
	"sys$login:", "emacs_dir:",
#endif
	"sys$sysdevice:[vmstools]"
#endif
};

#define PATHNAME_SIZE (sizeof pathname / sizeof pathname[ 0])

int help(int f, int n)
{				/* give me some help!!!!
				   bring up a fake buffer and read the help file
				   into it with view mode                 */
	struct window *wp;	/* scaning pointer to windows */
	struct buffer *bp;	/* buffer pointer to help */
	char *fname = NULL;	/* ptr to file returned by flook() */

	/* first check if we are already here */
	bp = bfind("emacs.hlp", FALSE, BFINVS);

	if (bp == NULL) {
		fname = flook(pathname[1], FALSE);
		if (fname == NULL) {
			mlwrite("(Help file is not online)");
			return FALSE;
		}
	}

	/* split the current window to make room for the help stuff */
	if (splitwind(FALSE, 1) == FALSE)
		return FALSE;

	if (bp == NULL) {
		/* and read the stuff in */
		if (getfile(fname, FALSE) == FALSE)
			return FALSE;
	} else
		swbuffer(bp);

	/* make this window in VIEW mode, update all mode lines */
	curwp->w_bufp->b_mode |= MDVIEW;
	curwp->w_bufp->b_flag |= BFINVS;
	wp = wheadp;
	while (wp != NULL) {
		wp->w_flag |= WFMODE;
		wp = wp->w_wndp;
	}
	return TRUE;
}

int deskey(int f, int n)
{				/* describe the command for a certain key */
	int c;		/* key to describe */
	char *ptr;	/* string pointer to scan output strings */
	char outseq[NSTRING];	/* output buffer for command sequence */

	/* prompt the user to type us a key to describe */
	mlwrite(": describe-key ");

	/* get the command sequence to describe
	   change it to something we can print as well */
	cmdstr(c = getckey(FALSE), &outseq[0]);

	/* and dump it out */
	ostring(outseq);
	ostring(" ");

	/* find the right ->function */
	if ((ptr = getfname(getbind(c))) == NULL)
		ptr = "Not Bound";

	/* output the command sequence */
	ostring(ptr);
	return TRUE;
}

/*
 * bindtokey:
 *	add a new key to the key binding table
 *
 * int f, n;		command arguments [IGNORED]
 */
int bindtokey(int f, int n)
{
	unsigned int c;	     /* command key to bind */
	fn_t kfunc;	     /* ptr to the requested function to bind to */
	struct key_tab *ktp; /* pointer into the command table */
	int found;	     /* matched command flag */
	char outseq[80];     /* output buffer for keystroke sequence */

	/* prompt the user to type in a key to bind */
	mlwrite(": bind-to-key ");

	/* get the function name to bind it to */
	kfunc = getname();
	if (kfunc == NULL) {
		mlwrite("(No such function)");
		return FALSE;
	}
	ostring(" ");

	/* get the command sequence to bind */
	c = getckey((kfunc == metafn) || (kfunc == cex) ||
		    (kfunc == unarg) || (kfunc == ctrlg));

	/* change it to something we can print as well */
	cmdstr(c, &outseq[0]);

	/* and dump it out */
	ostring(outseq);

	/* if the function is a prefix key */
	if (kfunc == metafn || kfunc == cex ||
	    kfunc == unarg || kfunc == ctrlg) {

		/* search for an existing binding for the prefix key */
		ktp = &keytab[0];
		found = FALSE;
		while (ktp->k_fp != NULL) {
			if (ktp->k_fp == kfunc)
				unbindchar(ktp->k_code);
			++ktp;
		}

		/* reset the appropriate global prefix variable */
		if (kfunc == metafn)
			metac = c;
		if (kfunc == cex)
			ctlxc = c;
		if (kfunc == unarg)
			reptc = c;
		if (kfunc == ctrlg)
			abortc = c;
	}

	/* search the table to see if it exists */
	ktp = &keytab[0];
	found = FALSE;
	while (ktp->k_fp != NULL) {
		if (ktp->k_code == c) {
			found = TRUE;
			break;
		}
		++ktp;
	}

	if (found) {		/* it exists, just change it then */
		ktp->k_fp = kfunc;
	} else {		/* otherwise we need to add it to the end */
		/* if we run out of binding room, bitch */
		if (ktp >= &keytab[NBINDS]) {
			mlwrite("Binding table FULL!");
			return FALSE;
		}

		ktp->k_code = c;	/* add keycode */
		ktp->k_fp = kfunc;	/* and the function pointer */
		++ktp;		/* and make sure the next is null */
		ktp->k_code = 0;
		ktp->k_fp = NULL;
	}
	return TRUE;
}

/*
 * unbindkey:
 *	delete a key from the key binding table
 *
 * int f, n;		command arguments [IGNORED]
 */
int unbindkey(int f, int n)
{
	int c;		/* command key to unbind */
	char outseq[80];	/* output buffer for keystroke sequence */

	/* prompt the user to type in a key to unbind */
	mlwrite(": unbind-key ");

	/* get the command sequence to unbind */
	c = getckey(FALSE);	/* get a command sequence */

	/* change it to something we can print as well */
	cmdstr(c, &outseq[0]);

	/* and dump it out */
	ostring(outseq);

	/* if it isn't bound, bitch */
	if (unbindchar(c) == FALSE) {
		mlwrite("(Key not bound)");
		return FALSE;
	}
	return TRUE;
}


/*
 * unbindchar()
 *
 * int c;		command key to unbind
 */
int unbindchar(int c)
{
	struct key_tab *ktp;   /* pointer into the command table */
	struct key_tab *sktp;  /* saved pointer into the command table */
	int found;             /* matched command flag */

	/* search the table to see if the key exists */
	ktp = &keytab[0];
	found = FALSE;
	while (ktp->k_fp != NULL) {
		if (ktp->k_code == c) {
			found = TRUE;
			break;
		}
		++ktp;
	}

	/* if it isn't bound, bitch */
	if (!found)
		return FALSE;

	/* save the pointer and scan to the end of the table */
	sktp = ktp;
	while (ktp->k_fp != NULL)
		++ktp;
	--ktp;			/* backup to the last legit entry */

	/* copy the last entry to the current one */
	sktp->k_code = ktp->k_code;
	sktp->k_fp = ktp->k_fp;

	/* null out the last one */
	ktp->k_code = 0;
	ktp->k_fp = NULL;
	return TRUE;
}

/* describe bindings
 * bring up a fake buffer and list the key bindings
 * into it with view mode
 */
int desbind(int f, int n)
#if	APROP
{
	buildlist(TRUE, "");
	return TRUE;
}

int apro(int f, int n)
{				/* Apropos (List functions that match a substring) */
	char mstring[NSTRING];	/* string to match cmd names to */
	int status;		/* status return */

	status = mlreply("Apropos string: ", mstring, NSTRING - 1);
	if (status != TRUE)
		return status;

	return buildlist(FALSE, mstring);
}

/*
 * build a binding list (limited or full)
 *
 * int type;		true = full list,   false = partial list
 * char *mstring;	match string if a partial list
 */
int buildlist(int type, char *mstring)
#endif
{
	struct window *wp;         /* scanning pointer to windows */
	struct key_tab *ktp;  /* pointer into the command table */
	struct name_bind *nptr;          /* pointer into the name binding table */
	struct buffer *bp;    /* buffer to put binding list into */
	int cpos;             /* current position to use in outseq */
	char outseq[80];      /* output buffer for keystroke sequence */

	/* split the current window to make room for the binding list */
	if (splitwind(FALSE, 1) == FALSE)
		return FALSE;

	/* and get a buffer for it */
	bp = bfind("*Binding list*", TRUE, 0);
	if (bp == NULL || bclear(bp) == FALSE) {
		mlwrite("Can not display binding list");
		return FALSE;
	}

	/* let us know this is in progress */
	mlwrite("(Building binding list)");

	/* disconect the current buffer */
	if (--curbp->b_nwnd == 0) {	/* Last use.            */
		curbp->b_dotp = curwp->w_dotp;
		curbp->b_doto = curwp->w_doto;
		curbp->b_markp = curwp->w_markp;
		curbp->b_marko = curwp->w_marko;
	}

	/* connect the current window to this buffer */
	curbp = bp;		/* make this buffer current in current window */
	bp->b_mode = 0;		/* no modes active in binding list */
	bp->b_nwnd++;		/* mark us as more in use */
	wp = curwp;
	wp->w_bufp = bp;
	wp->w_linep = bp->b_linep;
	wp->w_flag = WFHARD | WFFORCE;
	wp->w_dotp = bp->b_dotp;
	wp->w_doto = bp->b_doto;
	wp->w_markp = NULL;
	wp->w_marko = 0;

	/* build the contents of this window, inserting it line by line */
	nptr = &names[0];
	while (nptr->n_func != NULL) {

		/* add in the command name */
		strcpy(outseq, nptr->n_name);
		cpos = strlen(outseq);

#if	APROP
		/* if we are executing an apropos command..... */
		if (type == FALSE &&
		    /* and current string doesn't include the search string */
		    strinc(outseq, mstring) == FALSE)
			goto fail;
#endif
		/* search down any keys bound to this */
		ktp = &keytab[0];
		while (ktp->k_fp != NULL) {
			if (ktp->k_fp == nptr->n_func) {
				/* padd out some spaces */
				while (cpos < 28)
					outseq[cpos++] = ' ';

				/* add in the command sequence */
				cmdstr(ktp->k_code, &outseq[cpos]);
				strcat(outseq, "\n");

				/* and add it as a line into the buffer */
				if (linstr(outseq) != TRUE)
					return FALSE;

				cpos = 0;	/* and clear the line */
			}
			++ktp;
		}

		/* if no key was bound, we need to dump it anyway */
		if (cpos > 0) {
			outseq[cpos++] = '\n';
			outseq[cpos] = 0;
			if (linstr(outseq) != TRUE)
				return FALSE;
		}

	      fail:		/* and on to the next name */
		++nptr;
	}

	curwp->w_bufp->b_mode |= MDVIEW;	/* put this buffer view mode */
	curbp->b_flag &= ~BFCHG;	/* don't flag this as a change */
	wp->w_dotp = lforw(bp->b_linep);	/* back to the beginning */
	wp->w_doto = 0;
	wp = wheadp;		/* and update ALL mode lines */
	while (wp != NULL) {
		wp->w_flag |= WFMODE;
		wp = wp->w_wndp;
	}
	mlwrite("");		/* clear the mode line */
	return TRUE;
}

#if	APROP

/*
 * does source include sub?
 *
 * char *source;	string to search in
 * char *sub;		substring to look for
 */
int strinc(char *source, char *sub)
{
	char *sp;		/* ptr into source */
	char *nxtsp;		/* next ptr into source */
	char *tp;		/* ptr into substring */

	/* for each character in the source string */
	sp = source;
	while (*sp) {
		tp = sub;
		nxtsp = sp;

		/* is the substring here? */
		while (*tp) {
			if (*nxtsp++ != *tp)
				break;
			else
				tp++;
		}

		/* yes, return a success */
		if (*tp == 0)
			return TRUE;

		/* no, onward */
		sp++;
	}
	return FALSE;
}
#endif

/*
 * get a command key sequence from the keyboard
 *
 * int mflag;		going for a meta sequence?
 */
unsigned int getckey(int mflag)
{
	unsigned int c;	/* character fetched */
	char tok[NSTRING];	/* command incoming */

	/* check to see if we are executing a command line */
	if (clexec) {
		macarg(tok);	/* get the next token */
		return stock(tok);
	}

	/* or the normal way */
	if (mflag)
		c = get1key();
	else
		c = getcmd();
	return c;
}

/*
 * execute the startup file
 *
 * char *sfname;	name of startup file (null if default)
 */
int startup(char *sfname)
{
	char *fname;		/* resulting file name to execute */

	/* look up the startup file */
	if (*sfname != 0)
		fname = flook(sfname, TRUE);
	else
		fname = flook(pathname[0], TRUE);

	/* if it isn't around, don't sweat it */
	if (fname == NULL)
		return TRUE;

	/* otherwise, execute the sucker */
	return dofile(fname);
}

/*
 * Look up the existance of a file along the normal or PATH
 * environment variable. Look first in the HOME directory if
 * asked and possible
 *
 * char *fname;		base file name to search for
 * int hflag;		Look in the HOME environment variable first?
 */
char *flook( const char *fname, int hflag)
{
	char *home;	/* path to home directory */
	char *path;	/* environmental PATH variable */
	char *sp;	/* pointer into path spec */
	int i;		/* index */
	static char fspec[NSTRING];	/* full path spec to search */

#if	ENVFUNC

	if (hflag) {
		home = getenv("HOME");
		if (home != NULL) {
			/* build home dir file spec */
			strcpy(fspec, home);
			strcat(fspec, "/");
			strcat(fspec, fname);

			/* and try it out */
			if (ffropen(fspec) == FIOSUC) {
				ffclose();
				return fspec;
			}
		}
	}
#endif

	/* always try the current directory first */
	strcpy( fspec, fname) ;
	if( ffropen( fspec) == FIOSUC) {
		ffclose() ;
		return fspec ;
	}
#if	ENVFUNC
	/* get the PATH variable */
	path = getenv("PATH");
	if (path != NULL)
		while (*path) {

			/* build next possible file spec */
			sp = fspec;
			while (*path && (*path != PATHCHR))
				*sp++ = *path++;

			/* add a terminating dir separator if we need it */
			if (sp != fspec)
				*sp++ = '/';
			*sp = 0;
			strcat(fspec, fname);

			/* and try it out */
			if (ffropen(fspec) == FIOSUC) {
				ffclose();
				return fspec;
			}

			if (*path == PATHCHR)
				++path;
		}
#endif

	/* look it up via the old table method */
	for( i = 2; i < PATHNAME_SIZE ; i++) {
		strcpy(fspec, pathname[i]);
		strcat(fspec, fname);

		/* and try it out */
		if (ffropen(fspec) == FIOSUC) {
			ffclose();
			return fspec;
		}
	}

	return NULL;		/* no such luck */
}

/*
 * change a key command to a string we can print out
 *
 * int c;		sequence to translate
 * char *seq;		destination string for sequence
 */
void cmdstr(int c, char *seq)
{
	char *ptr;		/* pointer into current position in sequence */

	ptr = seq;

	/* apply meta sequence if needed */
	if (c & META) {
		*ptr++ = 'M';
		*ptr++ = '-';
	}

	/* apply ^X sequence if needed */
	if (c & CTLX) {
		*ptr++ = '^';
		*ptr++ = 'X';
	}

	/* apply SPEC sequence if needed */
	if (c & SPEC) {
		*ptr++ = 'F';
		*ptr++ = 'N';
	}

	/* apply control sequence if needed */
	if (c & CONTROL) {
		*ptr++ = '^';
	}

	/* and output the final sequence */

	*ptr++ = c & 255;	/* strip the prefixes */

	*ptr = 0;		/* terminate the string */
}

/*
 * This function looks a key binding up in the binding table
 *
 * int c;		key to find what is bound to it
 */
int (*getbind(int c))(int, int)
{
	struct key_tab *ktp;

	ktp = &keytab[0];  /* Look in key table. */
	while (ktp->k_fp != NULL) {
		if (ktp->k_code == c)
			return ktp->k_fp;
		++ktp;
	}

	/* no such binding */
	return NULL;
}

/*
 * getfname:
 *	This function takes a ptr to function and gets the name
 *	associated with it.
 */
char *getfname(fn_t func)
{
	struct name_bind *nptr;	/* pointer into the name binding table */

	/* skim through the table, looking for a match */
	nptr = &names[0];
	while (nptr->n_func != NULL) {
		if (nptr->n_func == func)
			return nptr->n_name;
		++nptr;
	}
	return NULL;
}

/*
 * match fname to a function in the names table
 * and return any match or NULL if none
 *
 * char *fname;		name to attempt to match
 */
int (*fncmatch(char *fname)) (int, int)
{
	struct name_bind *ffp;	/* pointer to entry in name binding table */

	/* scan through the table, returning any match */
	ffp = &names[0];
	while (ffp->n_func != NULL) {
		if (strcmp(fname, ffp->n_name) == 0)
			return ffp->n_func;
		++ffp;
	}
	return NULL;
}

/*
 * stock:
 *	String key name TO Command Key
 *
 * char *keyname;	name of key to translate to Command key form
 */
unsigned int stock(char *keyname)
{
	unsigned int c;	/* key sequence to return */

	/* parse it up */
	c = 0;

	/* first, the META prefix */
	if (*keyname == 'M' && *(keyname + 1) == '-') {
		c = META;
		keyname += 2;
	}

	/* next the function prefix */
	if (*keyname == 'F' && *(keyname + 1) == 'N') {
		c |= SPEC;
		keyname += 2;
	}

	/* control-x as well... (but not with FN) */
	if (*keyname == '^' && *(keyname + 1) == 'X' && !(c & SPEC)) {
		c |= CTLX;
		keyname += 2;
	}

	/* a control char? */
	if (*keyname == '^' && *(keyname + 1) != 0) {
		c |= CONTROL;
		++keyname;
	}
	if (*keyname < 32) {
		c |= CONTROL;
		*keyname += 'A';
	}


	/* make sure we are not lower case (not with function keys) */
	if (*keyname >= 'a' && *keyname <= 'z' && !(c & SPEC))
		*keyname -= 32;

	/* the final sequence... */
	c |= *keyname;
	return c;
}

/*
 * string key name to binding name....
 *
 * char *skey;		name of keey to get binding for
 */
char *transbind(char *skey)
{
	char *bindname;

	bindname = getfname(getbind(stock(skey)));
	if (bindname == NULL)
		bindname = "ERROR";

	return bindname;
}